Friction draft-gear.



J. F. GOURSON.

FRICTION DRAFT GEAR.

APPLICATION FILED MAY 3, 1911.

Patented July 15, 1913.

2 SHEETS-SHEET 1.

L To a ll who'm, it ma concern full y described.

her end of the'gear only.

UNITE STAi QIES raigraar r1 oHN'F. COURSON, OLE-PITCAIRN, PE NSYIJVANIA. i

1 ICE.

" FRICTION DRAFT-Grime Be 'it-krrown-tliat I, JOHN F. CorfRso'N,

-a citizenofthe United States, residing at Pitcairn; in the county of Allegheny and State}of."Pennsylvania, have invented certain new "and usefuI'Improvements in F ric- 'tion Draft-Gears, of which the following is a specification.

My invention consists of an improvement in frictiol'i'drafti gears for railway cars, etc and it has for its object to provide frictional resistancebe'tween themselves and against the interior of the casing by means i of a group-or groups of segmental wedge blocks and ii ean's assembled therewith for ti'ansniittingito tlief several parts the pulling and buiiing strains.

The construction has in "view the creationof'high resistancefwit-h a minimum. of loiigitudinal movement and free 'relea seu These objectsare obtained by designing and assembling" the wedging and friction elements in the inanner hereinafter more In the'drawings: Figure 1 is a central'verticalsectional 'view, partlyin elevation, of one construction ot' the draft gearasseinbled, the parts being shown in extended position: Fig. 2 is ai'siinilar view, the central wedging members being shown in section. cross section on the line III, III otFig. 1". Figlaf is a similar section on the line TV, IV ofFig. l. Figs. 5, 6, 7 and 8 are detail views of the several friction wedge blocks used at the front end of the gear. Fig. 9 is a View similar to Fig. 1, the parts being shown in position under coinpression; Figs; 10, 11, 12 and 13 are views similarto Figs. 5 toS inclusive of the several friction wedge blocks used at the rear endjof the gear. Fig. 1st is a sectional plan View showing the construction and position of the partssl'iownin Fig. 1. Fig. 15 is a view similar to Fig.1 but showing the use of friction wedge blocks at the real or in- Fig. 16 is a detail View of the spring-bearing wedge ring shown in F ,1 5,

block or piece 7 is set against the rear end The front stops 9 are c aq -tas rept ,eaten'tea auiyiialiois. ap neaao'naieama 's;19m.-seira1nbxeae'sda of casing 5 against the outer end of which block bears the rounded'end S of yoke 3, preferably secured to the end ofthe'y'oke. shown. in dotted "lines in Fig. '1extendinginwardly at each side frornthe center sills 6, which sustainftl'ie pulling efl e'ct of the draft gear and impart it to said sills, while siinila'r' rear stops 10 act' to receiveand iiii'p'art butting strains in the sa1ne1nanner. I I M The simplestembodiment of the invention is shown in Fig. 1-5, employing an assenibled group of friction wedge blocks at the inner end only of the casing. These blocks are so shaped and arranged that when. grouped together within the cylinder they con'iprise a cylindrical sectional unit. Each block forms by its exterior face acylindrical frictionai bearingsuriace for'the inner face of the cylinder and each vided with tapering wedge faces, and each 'is segmental shape in cross section for. cornpact assemblage and internal friction; 'As shown in Fig. 15 the group consists of four longitudinally stationary b1och's12,"therear ends of which abut against the inner 'end of cylind'eiio. The front portions of said blocks 12 taper-at each side as at 13 providing wedge 'faces'for lateral separation thereof by the other to Wit, by the alternately disposed front Wedge blocks 14 or 15. There aretwoof each of said blocks 14 and 15, in pairs, oppositely locatedyz'; .6. blocks 14 are opposite each other between blocks'lQ, while blocks 15 are likewise opposite each other, alternateiy between blocks l. and between the other or opposite faces of blocks 12. i

The inner-portions of blocks 14 and 15 taperat angles corresponding to faces 13 of blocks 12 so that when inward pressure is exerted against either blocks 14 or 15 the effect will be toseparate adjacent bloc-ks 12 (as by blocks v14) and to force the "other blocks -15 forwardly in the cylinder. on the other hand, pressure isffirst exerted ini'vardly against blocks 15', then blocks 14: will be wedged forwardly.

In the construction "shown 'I' einployf a tapered hearing tingle, thefi'nner tapered face of which "be ai's'againstthe outer in wardly tapered endsi-of blocks 15 which are purposely made longer thanhlocks- 14, and arethus normally held a gainst thecylinder. The other-side.of-ringltiis flat, providing a bearing for pressure spring 17 whichbears by its other end against the usual follower 1S seated against the rear end of the draw bar 2 between the arms of yoke 3.

The central stem 19 extends inwardly 5 from follower 18 and in the normally open position of the gear as shown. terminates within ashort distance of the end of bearing limited capacity to the extent of its energy,

normally bears against the follower plate 18 and ring 16, tending to thrust blocks 15 inwardly to the extent of their travel and tightly against the adjacent faces of blocks 12. The inward thrust of blocks 15 tends to separate blocks 12 at each side of each block 15 and to thrust the adjacent blocks 12, 12 (one at each'side of block 14) toward and closely adjacent to each other. The blocks 14, located equidistantly between blocks 15 and opposite each other, are likewise by such action normally thrust forwardly to the position shown for engagement by end of stem 19 and at a location slightly beyond the inner end of bar 19 as in Fig. 15. Upon pulling strain being imparted to cylinder 5 through draw bar 2 and yoke 3 against stops 9, or buffing strain being imparted backwardly through dra-w bar 2, follower 18, spring 17 and stem 19 against the cylinder 5 and stops 10, the pri mary effect is. when the end -.of stem 19 .abuts against the extension 14' of wedge blocks 14, to separate the blocks 12, 12, at each side of wedge block 14, whereupon the blocks 12 acting against blocks 15, thrust them forwardly towardthe draw bar, carrying ring'16 forwardly against the compressing spring 17. The accumulated effect of in; ward travel of wedge blocks 14: under impact of the resistance of stem 19, either in pulling or buffing, and of the limited resisting pres sure of spring 17, is to effect lateral spreading of wedge blocks 12, the pairs of said blocks acting upon each converging side of blocks 15, thereby forcing said blocks forwardly within the casing in a direction opposite to the longitudinal travel of blocks 14. Due to the interengagement of the several segmental wedge block sections their radially contacting faces are in tight binding engagement with. each-other, as are also their several partly cylindrical faces with the interior surface of cylinder 5. The great strains and pressures developed by the interen'gaging wedges forcing the frictional faces of blocks 15 into tight binding engagement with the interior of cylinder 5 and against the accumulating pressure of 6- spring 17, result in a high degree of fricmally tional resistance between the several parts, both as to their external cylindrical faces, and their several radially disposed interengaging segmental faces.

It will be observed that, by the construction as thus constituted, the frictional travel I of the wedge blocks 14; and 15 is in opposite directions and against the inner surface while the annular frictional travel of the blocks 12 is also in opposite directions to each pair of blocks engaged by block 14, in directions annularly of the interior.- Also that the angles of the several wedge faces is such as to provide for free and ample release of the parts without sticking, upon release of either pulling or bufhng pressure.

\Vhat has just been said as to the construction, arrangement and operation of the parts equally describes the arrangement of the assembled wedge blocks at the inner end 5 of the cylinder in the principal figures of the drawings. These parts, being substantially the same with the exception of the in terposed ring 16, are identified by similar numerals and include, as an alternative construction, a relatively short stem 19 having an inner terminal head 19 adapted to norabut against the extensions 14 of wedge blocks 14. Said blocks together with the oppositely tapered blocks 12, 12, and the 9 5 spring-bearing friction blocks-15, 15 are retained in their normal position as shown in Fig. 1 by the usual spring 17, and a supplemental spring 17. Said spring 17* embraces stem 19 and also stem 19 which bears by its outer head 19 against the inner ends of frictional blocks 20, 20. Said blocks 20, like blocks 12, are in pairs, one block of each pair being located at each side of the main central wedge block 21, which in turn bear by their forward ends against the follower 18. Between the blocks 20 of said pair of blocks and the corresponding block 20 of the companion pair on the other side of the gear, are interposed the friction wedge blocks 22, 22, corresponding in position to blocks 15, as do blocks 21 correspond to blocks 14. The wedge faces of blocks 21, which produce the initial movement in the front set of wedge blocks, act against the adjacent com tacting faces of blocks 20, 20, to expand them laterally within the casing 5, apart from each other, while the opposite tapered wedge faces of said blocks 20, instead of being in clined in the opposite direction (as are the corresponding faces of blocks 12) are inclined in the same general direction as are the faces of blocks 20 which contact with faces of blocks 21. Likewise, the faces of the intermediate wedge blocks 22 are similarly disposed, making contact with the adjacent tapered faces of blocks 20. The effect of this construction is that as blocks 20 are separated by blocks 21 and act upon blocks 22, said blocks are thrust inwardly of the casing 5,

compressing spring 17. The general inward movement of'the entire assembled series of wedge blocks at the front of the casing also acts to thrust stem 19 inwardly until it makes contact with .stem 19, blocks 22 in the-meantime having been carried inwardly at a greater speed of travel than blocks 20, as in FigxS). Thereupon, stems 19'and 19, forming a rigid resisting abutment, further movement of either the draw bar in bufiing or of the casing 5 in pulling, operates to eX ert further expansion in each set of assembled blocks at front and back, producing proportionately increased expansion of the several blocks and frictional engagement by their cylindrical surfaces againstthe interior of the cylinder.

The operation of the apparatus will be readily understood from the foregoing description. The advantages result primarily in great frictional contact pressure between the friction blocks and casing within a com paratively short range of longitudinal move ment of the blocks and immediate and com plete separation of the binding parts upon release of bufling or pulling pressure. The parts are easily assembled and maintained in assembled relation by reason of the interfitting engagement of the several segmental shaped wedge blocks, while the practically continuous cylindrical surfaces thereof insure a symmetrical disposition of the wearing strains with equal wear throughout.

Having described my invention what I claim is:

1. The combination with a casing and a relatively movable drawbar;

of a unitary series of annularly assembled wedge blocks within the casing having contacting angle faces; of varying inclination, and means adapted to impart longitudinal movement to some of said blocks. 4

2. The combination with a casing and a relatively'movable drawbar; of a unitary series of annular-1y assembled wedge blocks within the casing having outer cylindrical faces engaging the casing and inter-engaging radially disposed angle wedge faces of varying inclination with relation to the longitudinal center of the casing, said blocks engaging each other by their contacting wedge faces transversely of the series, and means adapted to' impart longitudinal movement to some of said blocks.

3. In combination, a casing, a 'drawbar in operative relation thereto, a follower, stop abutments, a plurality of cylindrical unitary groups of wedge blocks within the casing each group comprising alternately arranged longitudinally and laterally movable friction members each having a tapered forma-' tion providing opposite Wedge faces, a spring interposed between said groups of blocks, and a stem adapts. to transmit pressure from certain of the blocks of one group to certain of the blocks of the other group.

In testimony whereof I hereunto aiiix my signature in the presence of two witnesses.

JOHN F. COURSON. Witnesses C. M. CLARKE, CHAS. S. LEPLEY. 

